Most plastics are combustible and comparatively highly flammable. To reduce or preclude the risk of plastics burning in particular applications, it is therefore required to lower the flammability and/or to deploy flame-proof plastic compositions. For this purpose, flame retardants are usually added to the plastic with the aim of preventing igniting for a certain time or to significantly delay the spread of fire. Traditional flame retardants are based on chlorine- and bromine-containing compounds (frequently in combination with antimony trioxide), of phosphoric and nitrogenous compounds and of inorganic hydroxides. More recently, for environmental reasons, halogen-free fire proofing solutions are preferred.
EP 1 657 972 B1 relates to phosphinate complex compounds of the 2nd, 3rd, 12th and 13th groups and their use as flame retardants. In particular, phosphinate complexes of the formula

are described, in which M is one of the metals of the second, third, twelfth or thirteenth group of the periodic system of the elements;
x denotes the number 2 or 3;
R denotes a hydrogen atom or a 2 hydroxyphenyl residue;
B denotes a Lewis base;
y denotes the number 1 or 2; and
n denotes an integer from 1 to 100.
EP 2 183 314 B1 relates to phosphoric triazine compounds as fire retardants. In particular, compounds of the formula [(A-H)+]m [Mm+(HPO42−)m] and the formula [(A-H)+]m[Mm+(P2O74−)m/2] are disclosed, wherein (A-H)+ is a residue of the formula

and wherein X is H, CN, C(NH)NH2, C(O)NH2, C(NH)NHCN or its condensation product, wherein M is, independently of one another, Ca, Mg, Zn or Al and wherein m is 2 or 3.
A flame retardant composition is known from WO 2012/025362 which has at least one triazine-intercalated metal phosphate of the formula(A-H)a(+)[Mbm+(H2PO4)x1(−)(HPO4)x22(−)(PO4)x33(−)(PO3)y(−)](a−).pH2O
and comprises at least one additional flame retardant component. Here, each M is independently Cu, Mg, Ca, Zn, Mn, Fe, Co, Ni, TiO, ZrO, VO, B, Si, Al, Sb, La, Ti, Zr, Ce or Sn. The additional flame retardant component can be a metal phosphinate of the formula

wherein R1 and R2 is hydrogen or a straight-chain or a branched C1-C6 alkyl residue or a phenyl residue and Mt=Ca, Mg, Zn or Al and m=2 or 3.